[browser] add test of download re-try into advanced sample

src/mono/sample/wasm/browser-advanced/Wasm.Advanced.Sample.csproj

@@ -16,4 +16,7 @@
     <NativeFileReference Include="fibonacci.c" />
     <TrimmerRootDescriptor Include="$(MSBuildThisFileDirectory)ILLink.Descriptors.xml" />
   </ItemGroup>
+
+  <Target Name="RunSample" DependsOnTargets="RunSampleWithBrowserAndSimpleServer" />
+
 </Project>

src/mono/sample/wasm/browser-advanced/main.js

@@ -7,6 +7,9 @@ function add(a, b) {
     return a + b;
 }
 
+let testAbort = true;
+let testError = true;
+
 try {
     const { runtimeBuildInfo, setModuleImports, getAssemblyExports, runMain, getConfig, Module } = await dotnet
         .withElementOnExit()
@@ -22,6 +25,21 @@ try {
                 config.environmentVariables["MONO_LOG_LEVEL"] = "debug";
                 config.browserProfilerOptions = {};
             },
+            imports: {
+                fetch: (url, fetchArgs) => {
+                    console.log("fetching " + url);
+                    // we are testing that we can retry loading of the assembly
+                    if (testAbort && url.indexOf('System.Private.Uri.dll') != -1) {
+                        testAbort = false;
+                        return fetch(url + "?testAbort=true", fetchArgs);
+                    }
+                    if (testError && url.indexOf('System.Console.dll') != -1) {
+                        testError = false;
+                        return fetch(url + "?testError=true", fetchArgs);
+                    }
+                    return fetch(url, fetchArgs);
+                }
+            },
             preInit: () => { console.log('user code Module.preInit'); },
             preRun: () => { console.log('user code Module.preRun'); },
             onRuntimeInitialized: () => {

src/mono/sample/wasm/simple-server/Program.cs

@@ -156,19 +156,43 @@ private async void ServeAsync(HttpListenerContext context)
                 string? contentType = null;
                 if (path.EndsWith(".wasm"))
                     contentType = "application/wasm";
-                if (path.EndsWith(".webcil"))
+                if (path.EndsWith(".webcil") || path.EndsWith(".dll") || path.EndsWith(".pdb"))
                     contentType = "application/octet-stream";
                 if (path.EndsWith(".json"))
                     contentType = "application/json";
                 if (path.EndsWith(".js") || path.EndsWith(".mjs") || path.EndsWith(".cjs"))
                     contentType = "text/javascript";
 
+                var stream = context.Response.OutputStream;
+
+                // test download re-try
+                if (url.Query.Contains("testError"))
+                {
+                    Console.WriteLine("Faking 500 " + url);
+                    context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
+                    await stream.WriteAsync(buffer, 0, 0).ConfigureAwait(false);
+                    await stream.FlushAsync();
+                    context.Response.Close();
+                    return;
+                }
+
                 if (contentType != null)
                     context.Response.ContentType = contentType;
 
                 context.Response.ContentLength64 = buffer.Length;
                 context.Response.AppendHeader("cache-control", "public, max-age=31536000");
-                var stream = context.Response.OutputStream;
+
+                // test download re-try
+                if (url.Query.Contains("testAbort"))
+                {
+                    Console.WriteLine("Faking abort " + url);
+                    await stream.WriteAsync(buffer, 0, 10).ConfigureAwait(false);
+                    await stream.FlushAsync();
+                    await Task.Delay(100);
+                    context.Response.Abort();
+                    return;
+                }
+
                 try
                 {
                     await stream.WriteAsync(buffer).ConfigureAwait(false);